The sheer number of foodborne illness outbreaks tied to produce and vegetables in 2018 has a lot of Americans worried about the safety of their groceries. Rather than relying on federal agencies like the Food and Drug Administration, Walmart and Sam's Club have decided to use a new technology—called blockchain—that would track each and every piece of food they sell before it is placed on a store shelf—and they're starting with lettuce.

The decision to start with lettuce is a significant. Because it is grown in the ground, and eaten raw, lettuce is particularly susceptible to contamination, and because it is grown in multiple places, by multiple farmers, it can be particularly hard to track an outbreak. This year's E. coli outbreak linked to romaine lettuce was the largest that Americans have seen in over a decade, and despite their best efforts, officials failed to trace the source of contamination until months after.

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The process means that all the suppliers who sell lettuce to Walmart and Sam's Club will have to upload data about their products within the following year—including where it was sourced, which could help officials stop an outbreak from getting worse.

In a letter to its suppliers, Walmart said using technology to stringently trace each and every piece of produce is a way for the retailer to also strip their shelves of the affected product sooner, theNew York Times reports.

"Walmart believes the current one-step up and one-step back model of food traceability is outdated for the 21st Century and that by, working together, we can do better," Walmart wrote in its letter. "There is no question that there is a strong public-health and business-case for enhanced food traceability."

Customers lost faith in the grocer's lettuce selection, despite efforts to remove all lettuce sourced from the Yuma, Arizona region, Walmart says—mostly due to the delayed response by the FDA during the E. coli outbreak earlier this year. Tracking products using blockchain technology could enable Walmart to pull affected items "in seconds — not days," the big-box retailer says.

Walmart, which operates more than 5,300 storefronts including its membership-only Sam's Club locations, has given farmers and producers a deadline of September 30, 2019, to comply with new standards. The main goal is to have "end-to-end traceability" allowing the retailer to log each and every aspect of the production process before lettuce is sold in stores by then.

This isn't the first time that Walmart has experimented with blockchain technology—according to Supermarket News, the retail giant has been tracking groceries like mangoes and chicken for at least 18 months. It's unclear how much the new tracking system will actually cost farmers or food distributors, but IBM has launched a website to aid farmers in providing data about their crops directly to the retailer.